//========================================================//
// Cryptography des                                       //
// Author: Kozlov Dmitry aka LandFox kozlov@ccfit.nsu.ru  //
// NSU FIT September - October 2004                       //
//========================================================//


#include "des.h"

/* the eight DES S-boxes */

uint32 SB1[64] =
{
	0x01010400, 0x00000000, 0x00010000, 0x01010404,
		0x01010004, 0x00010404, 0x00000004, 0x00010000,
		0x00000400, 0x01010400, 0x01010404, 0x00000400,
		0x01000404, 0x01010004, 0x01000000, 0x00000004,
		0x00000404, 0x01000400, 0x01000400, 0x00010400,
		0x00010400, 0x01010000, 0x01010000, 0x01000404,
		0x00010004, 0x01000004, 0x01000004, 0x00010004,
		0x00000000, 0x00000404, 0x00010404, 0x01000000,
		0x00010000, 0x01010404, 0x00000004, 0x01010000,
		0x01010400, 0x01000000, 0x01000000, 0x00000400,
		0x01010004, 0x00010000, 0x00010400, 0x01000004,
		0x00000400, 0x00000004, 0x01000404, 0x00010404,
		0x01010404, 0x00010004, 0x01010000, 0x01000404,
		0x01000004, 0x00000404, 0x00010404, 0x01010400,
		0x00000404, 0x01000400, 0x01000400, 0x00000000,
		0x00010004, 0x00010400, 0x00000000, 0x01010004
};

static uint32 SB2[64] =
{
	0x80108020, 0x80008000, 0x00008000, 0x00108020,
		0x00100000, 0x00000020, 0x80100020, 0x80008020,
		0x80000020, 0x80108020, 0x80108000, 0x80000000,
		0x80008000, 0x00100000, 0x00000020, 0x80100020,
		0x00108000, 0x00100020, 0x80008020, 0x00000000,
		0x80000000, 0x00008000, 0x00108020, 0x80100000,
		0x00100020, 0x80000020, 0x00000000, 0x00108000,
		0x00008020, 0x80108000, 0x80100000, 0x00008020,
		0x00000000, 0x00108020, 0x80100020, 0x00100000,
		0x80008020, 0x80100000, 0x80108000, 0x00008000,
		0x80100000, 0x80008000, 0x00000020, 0x80108020,
		0x00108020, 0x00000020, 0x00008000, 0x80000000,
		0x00008020, 0x80108000, 0x00100000, 0x80000020,
		0x00100020, 0x80008020, 0x80000020, 0x00100020,
		0x00108000, 0x00000000, 0x80008000, 0x00008020,
		0x80000000, 0x80100020, 0x80108020, 0x00108000
};

static uint32 SB3[64] =
{
	0x00000208, 0x08020200, 0x00000000, 0x08020008,
		0x08000200, 0x00000000, 0x00020208, 0x08000200,
		0x00020008, 0x08000008, 0x08000008, 0x00020000,
		0x08020208, 0x00020008, 0x08020000, 0x00000208,
		0x08000000, 0x00000008, 0x08020200, 0x00000200,
		0x00020200, 0x08020000, 0x08020008, 0x00020208,
		0x08000208, 0x00020200, 0x00020000, 0x08000208,
		0x00000008, 0x08020208, 0x00000200, 0x08000000,
		0x08020200, 0x08000000, 0x00020008, 0x00000208,
		0x00020000, 0x08020200, 0x08000200, 0x00000000,
		0x00000200, 0x00020008, 0x08020208, 0x08000200,
		0x08000008, 0x00000200, 0x00000000, 0x08020008,
		0x08000208, 0x00020000, 0x08000000, 0x08020208,
		0x00000008, 0x00020208, 0x00020200, 0x08000008,
		0x08020000, 0x08000208, 0x00000208, 0x08020000,
		0x00020208, 0x00000008, 0x08020008, 0x00020200
};

static uint32 SB4[64] =
{
	0x00802001, 0x00002081, 0x00002081, 0x00000080,
		0x00802080, 0x00800081, 0x00800001, 0x00002001,
		0x00000000, 0x00802000, 0x00802000, 0x00802081,
		0x00000081, 0x00000000, 0x00800080, 0x00800001,
		0x00000001, 0x00002000, 0x00800000, 0x00802001,
		0x00000080, 0x00800000, 0x00002001, 0x00002080,
		0x00800081, 0x00000001, 0x00002080, 0x00800080,
		0x00002000, 0x00802080, 0x00802081, 0x00000081,
		0x00800080, 0x00800001, 0x00802000, 0x00802081,
		0x00000081, 0x00000000, 0x00000000, 0x00802000,
		0x00002080, 0x00800080, 0x00800081, 0x00000001,
		0x00802001, 0x00002081, 0x00002081, 0x00000080,
		0x00802081, 0x00000081, 0x00000001, 0x00002000,
		0x00800001, 0x00002001, 0x00802080, 0x00800081,
		0x00002001, 0x00002080, 0x00800000, 0x00802001,
		0x00000080, 0x00800000, 0x00002000, 0x00802080
};

static uint32 SB5[64] =
{
	0x00000100, 0x02080100, 0x02080000, 0x42000100,
		0x00080000, 0x00000100, 0x40000000, 0x02080000,
		0x40080100, 0x00080000, 0x02000100, 0x40080100,
		0x42000100, 0x42080000, 0x00080100, 0x40000000,
		0x02000000, 0x40080000, 0x40080000, 0x00000000,
		0x40000100, 0x42080100, 0x42080100, 0x02000100,
		0x42080000, 0x40000100, 0x00000000, 0x42000000,
		0x02080100, 0x02000000, 0x42000000, 0x00080100,
		0x00080000, 0x42000100, 0x00000100, 0x02000000,
		0x40000000, 0x02080000, 0x42000100, 0x40080100,
		0x02000100, 0x40000000, 0x42080000, 0x02080100,
		0x40080100, 0x00000100, 0x02000000, 0x42080000,
		0x42080100, 0x00080100, 0x42000000, 0x42080100,
		0x02080000, 0x00000000, 0x40080000, 0x42000000,
		0x00080100, 0x02000100, 0x40000100, 0x00080000,
		0x00000000, 0x40080000, 0x02080100, 0x40000100
};

static uint32 SB6[64] =
{
	0x20000010, 0x20400000, 0x00004000, 0x20404010,
		0x20400000, 0x00000010, 0x20404010, 0x00400000,
		0x20004000, 0x00404010, 0x00400000, 0x20000010,
		0x00400010, 0x20004000, 0x20000000, 0x00004010,
		0x00000000, 0x00400010, 0x20004010, 0x00004000,
		0x00404000, 0x20004010, 0x00000010, 0x20400010,
		0x20400010, 0x00000000, 0x00404010, 0x20404000,
		0x00004010, 0x00404000, 0x20404000, 0x20000000,
		0x20004000, 0x00000010, 0x20400010, 0x00404000,
		0x20404010, 0x00400000, 0x00004010, 0x20000010,
		0x00400000, 0x20004000, 0x20000000, 0x00004010,
		0x20000010, 0x20404010, 0x00404000, 0x20400000,
		0x00404010, 0x20404000, 0x00000000, 0x20400010,
		0x00000010, 0x00004000, 0x20400000, 0x00404010,
		0x00004000, 0x00400010, 0x20004010, 0x00000000,
		0x20404000, 0x20000000, 0x00400010, 0x20004010
};

static uint32 SB7[64] =
{
	0x00200000, 0x04200002, 0x04000802, 0x00000000,
		0x00000800, 0x04000802, 0x00200802, 0x04200800,
		0x04200802, 0x00200000, 0x00000000, 0x04000002,
		0x00000002, 0x04000000, 0x04200002, 0x00000802,
		0x04000800, 0x00200802, 0x00200002, 0x04000800,
		0x04000002, 0x04200000, 0x04200800, 0x00200002,
		0x04200000, 0x00000800, 0x00000802, 0x04200802,
		0x00200800, 0x00000002, 0x04000000, 0x00200800,
		0x04000000, 0x00200800, 0x00200000, 0x04000802,
		0x04000802, 0x04200002, 0x04200002, 0x00000002,
		0x00200002, 0x04000000, 0x04000800, 0x00200000,
		0x04200800, 0x00000802, 0x00200802, 0x04200800,
		0x00000802, 0x04000002, 0x04200802, 0x04200000,
		0x00200800, 0x00000000, 0x00000002, 0x04200802,
		0x00000000, 0x00200802, 0x04200000, 0x00000800,
		0x04000002, 0x04000800, 0x00000800, 0x00200002
};

static uint32 SB8[64] =
{
	0x10001040, 0x00001000, 0x00040000, 0x10041040,
		0x10000000, 0x10001040, 0x00000040, 0x10000000,
		0x00040040, 0x10040000, 0x10041040, 0x00041000,
		0x10041000, 0x00041040, 0x00001000, 0x00000040,
		0x10040000, 0x10000040, 0x10001000, 0x00001040,
		0x00041000, 0x00040040, 0x10040040, 0x10041000,
		0x00001040, 0x00000000, 0x00000000, 0x10040040,
		0x10000040, 0x10001000, 0x00041040, 0x00040000,
		0x00041040, 0x00040000, 0x10041000, 0x00001000,
		0x00000040, 0x10040040, 0x00001000, 0x00041040,
		0x10001000, 0x00000040, 0x10000040, 0x10040000,
		0x10040040, 0x10000000, 0x00040000, 0x10001040,
		0x00000000, 0x10041040, 0x00040040, 0x10000040,
		0x10040000, 0x10001000, 0x10001040, 0x00000000,
		0x10041040, 0x00041000, 0x00041000, 0x00001040,
		0x00001040, 0x00040040, 0x10000000, 0x10041000
};

/* PC1: left and right halves bit-swap */

static uint32 LHs[16] =
{
	0x00000000, 0x00000001, 0x00000100, 0x00000101,
		0x00010000, 0x00010001, 0x00010100, 0x00010101,
		0x01000000, 0x01000001, 0x01000100, 0x01000101,
		0x01010000, 0x01010001, 0x01010100, 0x01010101
};

static uint32 RHs[16] =
{
	0x00000000, 0x01000000, 0x00010000, 0x01010000,
		0x00000100, 0x01000100, 0x00010100, 0x01010100,
		0x00000001, 0x01000001, 0x00010001, 0x01010001,
		0x00000101, 0x01000101, 0x00010101, 0x01010101,
};

/* platform-independant 32-bit integer manipulation macros */
inline void GET_UINT32(uint32& n,const uint8 * b, int i) {
	n = (uint32)b[i] << 24 | (uint32) b[i + 1] << 16 | (uint32) b[i + 2] <<  8 | (uint32) b[i + 3];
}

inline void PUT_UINT32(const uint32& n, uint8 *b, int i) {
	b[i] = (uint8)(n >> 24);
	b[i + 1] = (uint8)(n >> 16);
	b[i + 2] = (uint8)(n >>  8);
	b[i + 3] = (uint8)n;
}

inline void DES_IP(uint32& X, uint32& Y, uint32& T) {
	T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);
	T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);
	T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);
	T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);
	Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF;
	T = (X ^ Y) & 0xAAAAAAAA; Y ^= T; X ^= T;
	X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF;
}

inline void DES_FP(uint32& X, uint32& Y, uint32& T) {
	X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF;
	T = (X ^ Y) & 0xAAAAAAAA; X ^= T; Y ^= T;
	Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF;
	T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);
	T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);
	T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);
	T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);
}

inline void DES_ROUND(uint32& X, uint32 &Y, uint32& T, uint32 *& SK) {
	T = *SK++ ^ X;
	Y ^= SB8[ T & 0x3F ] ^ SB6[ (T >>  8) & 0x3F ] ^ SB4[ (T >> 16) & 0x3F ] ^ SB2[ (T >> 24) & 0x3F ];
	T = *SK++ ^ ((X << 28) | (X >> 4));
	Y ^= SB7[ T & 0x3F ] ^ SB5[ (T >>  8) & 0x3F ] ^ SB3[ (T >> 16) & 0x3F ] ^ SB1[ (T >> 24) & 0x3F ];
}

int des_main_ks( uint32 SK[32], const uint8 key[8] )
{
	int i;
	uint32 X, Y, T;

	GET_UINT32( X, key, 0 );
	GET_UINT32( Y, key, 4 );

	/* Permuted Choice 1 */

	T =  ((Y >>  4) ^ X) & 0x0F0F0F0F;  X ^= T; Y ^= (T <<  4);
	T =  ((Y      ) ^ X) & 0x10101010;  X ^= T; Y ^= (T      );

	X =   (LHs[ (X      ) & 0xF] << 3) | (LHs[ (X >>  8) & 0xF ] << 2)
		| (LHs[ (X >> 16) & 0xF] << 1) | (LHs[ (X >> 24) & 0xF ]     )
		| (LHs[ (X >>  5) & 0xF] << 7) | (LHs[ (X >> 13) & 0xF ] << 6)
		| (LHs[ (X >> 21) & 0xF] << 5) | (LHs[ (X >> 29) & 0xF ] << 4);

	Y =   (RHs[ (Y >>  1) & 0xF] << 3) | (RHs[ (Y >>  9) & 0xF ] << 2)
		| (RHs[ (Y >> 17) & 0xF] << 1) | (RHs[ (Y >> 25) & 0xF ]     )
		| (RHs[ (Y >>  4) & 0xF] << 7) | (RHs[ (Y >> 12) & 0xF ] << 6)
		| (RHs[ (Y >> 20) & 0xF] << 5) | (RHs[ (Y >> 28) & 0xF ] << 4);

	X &= 0x0FFFFFFF;
	Y &= 0x0FFFFFFF;

	/* calculate subkeys */

	for( i = 0; i < 16; i++ )
	{
		if( i < 2 || i == 8 || i == 15 )
		{
			X = ((X <<  1) | (X >> 27)) & 0x0FFFFFFF;
			Y = ((Y <<  1) | (Y >> 27)) & 0x0FFFFFFF;
		}
		else
		{
			X = ((X <<  2) | (X >> 26)) & 0x0FFFFFFF;
			Y = ((Y <<  2) | (Y >> 26)) & 0x0FFFFFFF;
		}

		*SK++ =   ((X <<  4) & 0x24000000) | ((X << 28) & 0x10000000)
			| ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000)
			| ((X <<  6) & 0x01000000) | ((X <<  9) & 0x00200000)
			| ((X >>  1) & 0x00100000) | ((X << 10) & 0x00040000)
			| ((X <<  2) & 0x00020000) | ((X >> 10) & 0x00010000)
			| ((Y >> 13) & 0x00002000) | ((Y >>  4) & 0x00001000)
			| ((Y <<  6) & 0x00000800) | ((Y >>  1) & 0x00000400)
			| ((Y >> 14) & 0x00000200) | ((Y      ) & 0x00000100)
			| ((Y >>  5) & 0x00000020) | ((Y >> 10) & 0x00000010)
			| ((Y >>  3) & 0x00000008) | ((Y >> 18) & 0x00000004)
			| ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001);

		*SK++ =   ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000)
			| ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000)
			| ((X >>  2) & 0x02000000) | ((X <<  1) & 0x01000000)
			| ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000)
			| ((X <<  3) & 0x00080000) | ((X >>  6) & 0x00040000)
			| ((X << 15) & 0x00020000) | ((X >>  4) & 0x00010000)
			| ((Y >>  2) & 0x00002000) | ((Y <<  8) & 0x00001000)
			| ((Y >> 14) & 0x00000808) | ((Y >>  9) & 0x00000400)
			| ((Y      ) & 0x00000200) | ((Y <<  7) & 0x00000100)
			| ((Y >>  7) & 0x00000020) | ((Y >>  3) & 0x00000011)
			| ((Y <<  2) & 0x00000004) | ((Y >> 21) & 0x00000002);
	}

	return( 0 );
}

int des_set_key( des_context *ctx, uint8 key[8] )
{
	int i;

	/* setup encryption subkeys */

	des_main_ks( ctx->esk, key );

	/* setup decryption subkeys */

	for( i = 0; i < 32; i += 2 )
	{
		ctx->dsk[i    ] = ctx->esk[30 - i];
		ctx->dsk[i + 1] = ctx->esk[31 - i];
	}

	return( 0 );
}

/* DES 64-bit block encryption/decryption */

void des_crypt( uint32 SK[32], uint8 input[8], uint8 output[8] )
{
	uint32 X, Y, T;
	uint8 i;

	GET_UINT32( X, input, 0 );
	GET_UINT32( Y, input, 4 );

	DES_IP( X, Y, T);

	for(i = 0; i < 8; i++ ) {
		DES_ROUND( Y, X ,T ,SK );
		DES_ROUND( X, Y ,T ,SK );
	}

	DES_FP( Y, X ,T);

	PUT_UINT32( Y, output, 0 );
	PUT_UINT32( X, output, 4 );
}

void des_encrypt( des_context *ctx, uint8 input[8], uint8 output[8] )
{
	des_crypt( ctx->esk, input, output );
}

void des_decrypt( des_context *ctx, uint8 input[8], uint8 output[8] )
{
	des_crypt( ctx->dsk, input, output );
}

/* Triple-DES key schedule */

int des3_set_2keys( des3_context *ctx, const uint8 key1[8], const uint8 key2[8] )
{
	int i;

	des_main_ks( ctx->esk     , key1 );
	des_main_ks( ctx->dsk + 32, key2 );

	for( i = 0; i < 32; i += 2 )
	{
		ctx->dsk[i     ] = ctx->esk[30 - i];
		ctx->dsk[i +  1] = ctx->esk[31 - i];

		ctx->esk[i + 32] = ctx->dsk[62 - i];
		ctx->esk[i + 33] = ctx->dsk[63 - i];

		ctx->esk[i + 64] = ctx->esk[     i];
		ctx->esk[i + 65] = ctx->esk[ 1 + i];

		ctx->dsk[i + 64] = ctx->dsk[     i];
		ctx->dsk[i + 65] = ctx->dsk[ 1 + i];
	}

	return( 0 );
}

int des3_set_3keys( des3_context *ctx, uint8 key1[8], uint8 key2[8],
				   uint8 key3[8] )
{
	int i;

	des_main_ks( ctx->esk     , key1 );
	des_main_ks( ctx->dsk + 32, key2 );
	des_main_ks( ctx->esk + 64, key3 );

	for( i = 0; i < 32; i += 2 )
	{
		ctx->dsk[i     ] = ctx->esk[94 - i];
		ctx->dsk[i +  1] = ctx->esk[95 - i];

		ctx->esk[i + 32] = ctx->dsk[62 - i];
		ctx->esk[i + 33] = ctx->dsk[63 - i];

		ctx->dsk[i + 64] = ctx->esk[30 - i];
		ctx->dsk[i + 65] = ctx->esk[31 - i];
	}

	return( 0 );
}

/* Triple-DES 64-bit block encryption/decryption */

void des3_crypt( uint32 SK[96], const uint8 input[8], uint8 output[8] )
{
	uint32 X, Y, T;
	uint8 i;

	GET_UINT32( X, input, 0 );
	GET_UINT32( Y, input, 4 );

	DES_IP( X, Y, T);

	for(i = 0; i < 8; i ++) {
		DES_ROUND( Y, X, T, SK );
		DES_ROUND( X, Y, T, SK );
	}

	for(i = 0; i < 8; i ++) {
		DES_ROUND( X, Y, T, SK );
		DES_ROUND( Y, X, T, SK );
	}

	for(i = 0; i < 8; i ++) {
		DES_ROUND( Y, X, T, SK );
		DES_ROUND( X, Y, T, SK );
	}

	DES_FP( Y, X, T);

	PUT_UINT32( Y, output, 0 );
	PUT_UINT32( X, output, 4 );
}

void des3_encrypt( des3_context *ctx, const uint8 input[8], uint8 output[8] )
{
	des3_crypt( ctx->esk, input, output );
}

void des3_decrypt( des3_context *ctx, const uint8 input[8], uint8 output[8] )
{
	des3_crypt( ctx->dsk, input, output );
}


